How do you judge kyu tests?

Basicaly thekids in my cl are totaly clueless! I take notes all through out cl on their technique (what I have told them to correct/ what they are doing better) behavior/ attitude. Then I have those notes with me when I test them. I test EVERYONE every 3-6 months. I simply don't p those who aren't ready and either refund their money or their next test is free, but I get a good idea of where the cl is when I have everyone doing their absolute best all together. But I don't just judge on preformance that day- if you try hard in cl, have all your stripes (little checks on kata, kihon, kumite) and just got nervous made small mistakes- if i think they are ready I will p them. But also if I think behavior is under par, they have bad ettiquite during testing then no matter how good they do they don't move up and I tell them their attitude is what is keeping them down. Latly I have all kinds of parents pissed at why cindy passed but little tommy didn't. (normaly i give an explanation way over their heads and when they are staring blankly i walk away) How do you judge kyu tests (and not piss of parents)?